Leaked ad explains why HTC's putting a 'Duo Camera' in its new One

Ever since a leaked image showed off dual cameras on HTC's next One (aka the M8), the rumor mill has been trying to figure out what they're for, exactly. Now, an ad from Australian carrier Telstra leaked to GSM Arena
appears to have removed any mystery. First off, the phone is referred
to as the "All New HTC One (M8)," in the copy, likely to distinguish it
from the last model. As predicted, the "Duo Camera," will bring improved
low-light capabilities and let you select the focus of a shot after
it's been taken, in a similar way to the Lytro camera.
You'll also be able to highlight significant areas of a shot, soften
the background and add 3D effects. The ad also revealed a full HD 5-inch
scratch-resistant screen, a step up from last year's 4.7-inch One,
along with dual "BoomSound" speakers. Finally, it showed the latest
Sense 6.0 version that'll let you double tap the screen to turn on the
phone and swipe to access apps and social info. After all that, if
there's anything left to learn, we'll find out in exactly two weeks.